In the four months since it made history as “the largest scam of its kind,” a now infamous IRS imposter telephone scam has escalated with a recent new spin.

As fraudsters continue to pose as agents with that agency or the U.S. Treasury Department in “live” calls that threaten arrest or deportation, along with the seizure of property, businesses and driver’s licenses, they’ve recently upped the ante to now also incorporate robocalls in this widespread ruse.

Either way, the story is the same: Scammers allege, often with abusive language, that phone call recipients owe money for back taxes and threaten drastic action if not immediately paid by Green Dot MoneyPak prepaid debit cards or wire transfer – payment methods the real IRS doesn’t request.

To make their threats appear authentic, many incoming calls fool recipients’ caller ID to display the IRS toll-free phone number – 800-829-1040.

The scammers, who may have foreign accents, cite common all-American names and badge numbers – John Smith, Sean White and Jason Clark are recent examples used.

But their most alarming (and fear-invoking) ploy is their ability to accurately cite the last four digits of some targets’ Social Security numbers. Officials have no public explanation on how the fraudsters obtained that information for this scam, which started last fall.

Hang up on these taxmen tricksters, and you can expect a follow-up email with similar threats – or another phone call in which the same or another imposter uses a different name, this time posing as local law enforcement and threatening impending arrest for failure to pay the supposedly owed money.

That’s what recently happened to Tim Leslie of Minnesota, who received a call from alleged IRS agent Sean White. The caller claimed that Leslie improperly filed his taxes and that unless he settled the debt, “one copy of this case will be sent to your local sheriff department and one copy will be sent to your employer where you work right now to inform them of your fraudulent activity.”

Here’s the rub: Leslie is currently chief deputy of a sheriff’s department and seeking election to be county sheriff. He called a friend who works as an IRS agent, and an agency investigator told him that some 60,000 Americans have been contacted in this fast-moving scam, “and some folks lost over $10,000 to these people,” Leslie told Minnesota TV station KARE.

That’s a threefold increase in reported contacts since March, when Treasury Inspector General for Tax Administration (TIGTA) Russell George issued a renewed warning about this calling scam. At that time, frightened taxpayers had already paid at least $1 million to scammers.

What to do if you contacted by tax imposters?

Despite possible frightening but fraudulent follow-up contact, hang up on phone calls and report the incident to the TIGTA (phone: 800-366-4484) and Federal Trade Commission, which also issued a recent warning about this scam.

If you receive an email purporting to be from the IRS or Treasury Department, forward it to phishing@irs.gov without clicking on any links or attachments, which may unleash malware. Neither agency ever sends unsolicited emails to taxpayers.

If you really owe taxes or there’s been a problem with filing your returns, the IRS will notify you by U.S. mail – not telephone. If you get a letter, call the IRS at 800-829-1040. Do not respond to callback numbers provided in robocalls.

Know that the IRS doesn’t seek payment by prepaid debit card or wire transfer. But scammers prefer those methods because they are hard to trace and can be redeemed anywhere in the world.

Occasionally, scammers in this ruse may ask for credit card payment, but don’t be fooled: The IRS doesn’t request plastic payments by telephone.

If scammers recite a portion of your SSN, consider placing a fraud alert or security freeze on your credit file with the three major credit reporting bureaus to reduce risk of identity theft.

For information about other scams, sign up for the Fraud Watch Network. You’ll receive email alerts with tips and resources to help you spot and avoid identity theft and fraud, and gain access to a network of experts, law enforcement and people in your community who will keep you up to date on the latest scams in your area.